Cutting mechanism for the paper strips of recording machines



March 31, 1931. F. SCHLETH 1,799,067

CUTTING MECHANISM FOR THE PAPER STRIPS 0F RECORDING MACHINES Filed Dec. 20, 1928 2 Sheets-Sheet l i u i 5 March 31, 1931. SCHLETH 1,799,067

CUTTING MECHANISM FOR THE PAPER STRIPS OF RECORDING MACHINES Filed Dec. 20, 1928 2 Sheets-Sheet 2 Patented Mar. 31, 1 931 "res FRIEDRICH. scnLnTn, or ESSEN, GERMANY, ssIenon '10 FRIEDQKRUPP AKTIEN- ensnmsonarr, or nssnn-on-rnn-nunn, GERMANY CUTTING MECHANISM FOR THE FAPEB STRIPS 0F RECORDING MACHINES Application filed December e0, 1928, Serial no. 327,385, and. in Germany March 22,1928.

The invention relates to mechanisms for cutting 01% the paper strip of recording machines and more particularly has reference to mechanisms of the type having two knives J the cutting edgesof which. are-moved past one another.

The purpose of the invention is to arrange.

a support, the surface of contact between the companion knife and the support being confined to a single point remote from the cutting edge of the companion knife. This enables the companlon knife to execute a limited. rocking motion in order to accurately adjust itself tothe movable knife. 1

A preferred embodiment of the invention is illustrated by way of example in the drawing which accompanies and forms part of this specification, and in which Figure 1 is an elevation, partly in section, of the improved cutting mechanism,

Figure 2 is-the corresponding front view,

Figure 3 is the top view thereof, and

Figure 4 is a vertical section of a modified mounting for the companion knife.

Referring to these figures, 1 denotes the movableknife of the mechanism,which,in this case, is a rotary one and the cutting portion of which hasa sector-shaped cross section, Figure 1. On both its ends the knife 1 has a full cylindrical portion 2, 3, Figure 2, and is mounted for rotation in the side walls 6, 7 of the cabinet of the printing mechanism of the machine by means of journals 4, 5. A rim of teeth 8, Figure 1, of the end portion 3 of knife 1 'is in mesh with a toothed segment 11, mounted on a journal 9, fixed in the cabinet wall 7, Figure 2. The segment 11 isunder the influence of a spring12, Figure Land is provided with a roller 13, which is held against a cam disk 14 by the spring 12. One

full revolution is imparted to disk 14 in each operation of the machine, The cam disk14 is so desig ed that during this. revolutio the knife 1 executes two successive oscillating motions in clockwise direction and back again, its cutting edge 15 pass ng the cutting edge 16 of a companion knife 17 co-operating with knife 1. V

In the position of rest of the mechanism the lower end of the paper strip 19, which is fed from above and passes through a guide 1 8,Figure 1, abuts on the pe-ripheral'surface 21 of knife 1. When the latter rotates this peripheral surface 21 releases the paper strip, which thereupon can be forwarded by the lengthof a check: When knife 1 returns its a cutting edge 15 arrives at the paper strip 19, that has been fed in theineant-ime, and 7 cuts off the fed section thereof, in co-operation with the cutting edge 16 0f the companionkni'fe 17. To support the knife 17, a transversebar 24, Figures 2 and 3, is mounted in the side walls, 6, 7 of the cabinet, by

' means of journals 25, 26. This bar is secured against 10113131011 03] an extension 27, Figure 3, fixed to the wall E by means of a bolt 23.

'In the middle of the rear side of the transverse bar 24 are fixed, by two scr ws 29, an

abutment plate 32- and arectangularlybent flat spring 33. The latter has, at themiddle of its front end a depression 34, Figures 1 and 2, which is in contact with knife 17 and urges it both againstfthe shell surface 21 of knife 1 and" the abutment plate 32, which latter'has a lip 35 on its upper edge, Figure 2. Owing to this arrangement the cutting edge'16, Figure- 1, exactly adjusts itself to the peripheral surface 21 of knife 1, which would not be the case under all conditions the compamon knife 1'! were supported at several points by the transverse bar 24.

The knife 17 has length such as to over- 2', 3, Figure 2, of knife 1, so that it is held in the positionshown' in Figure 1- bythem when ral surface of knitel, plate 38; Figures lap, in part, the full cylindrical extremities 1 and 8, screwed on the front face of the transverse bar 24;, and a yoke 39, embracing knife 17 and likewise screwed on bar 2 1, serve to guide the paper strip 19. Two sheet metal pieces 41. 12. Figures 2 and 3, bent over the knife 17 protect it from springingout.

In place of the flat spring 33 a rigid abutment 50 may be provided, as shown in Figure 4. which has a set screw 51 in contact with knife 17. instead of by the depression 34.

The holes 43, Figure 2, receiving the screws 29, of the abutment plate 32, are slot-shaped, in order to permit plate 32 to be shifted in vertical direction, to impart to knife 17 different inclined positions and to thereby obtain the best cutting angle of the cutting, edge 16.

What I claim and desire to secure by Letters Patent, is

1. In a cutting mechanism. a movable knife, a support, a substantially stationary companion knife resting; upon said movable knife and said support, the contact between said support and said companion knife beins; confined to a single point about which said companion knife is free to rock to conform to said movable knife.

2. In a cutting mechanism. a movable knife, a support, a substantia ly stationary companion knife resting upon said movable knife and said support, the contact between said support and said companion knife beingz confined to a single point about which said companion knife is free to rock to conform to said movable knife. and means exerting a force on said companion knife tendine to hold the same against said support and said movable knife.

3. In a cutting mechanism, a rotary knife, a support, substantially stationary companion knife resting; at its cutting; edge upon the periphery of said rotary knife and at its opposite edge upon said support, the surface of Contact between said support and said companion knife being confined to a single point substantially at the middle of said opposite edge. and spring means exerting a force on said companion knife at a single point between said cutting edge and said opposite edge. 4

4:. The combination with a cutting mechanism as described in claim 1 of means for limiting lateral motion of said companion knife comprising; stationary pins, said companion knife having holes in which said pins engage with such play as to offer no hindrance to the rocking of said. companion knife.

5. A cutting mechanism as described in claim 1, in which said support is mounted so as to be adjustable in a direction substantially normal to said companion knife, whereby the angle between said knives can be adjusted.

The foregoing specification signed at Cologne, Germany, this 30th day of November,1928.

FRIEDRICH SCHLETH. 

